--- a/tests/test-drawdag.t	Mon Jun 26 23:31:53 2017 -0700
+++ b/tests/test-drawdag.t	Tue Jun 27 00:01:17 2017 -0700
@@ -1,6 +1,8 @@
   $ cat >> $HGRCPATH<<EOF
   > [extensions]
   > drawdag=$TESTDIR/drawdag.py
+  > [experimental]
+  > evolution=all
   > EOF
 
   $ reinit () {
@@ -178,3 +180,43 @@
   > EOS
   abort: the graph has cycles
   [255]
+
+Create obsmarkers via comments
+
+  $ reinit
+
+  $ hg debugdrawdag <<'EOS'
+  >       G
+  >       |
+  > I D C F   # split: B -> E, F, G
+  >  \ \| |   # replace: C -> D -> H
+  >   H B E   # prune: F, I
+  >    \|/
+  >     A
+  > EOS
+
+  $ hg log -r 'sort(all(), topo)' -G --hidden -T '{desc} {node}'
+  o  G 711f53bbef0bebd12eb6f0511d5e2e998b984846
+  |
+  x  F 64a8289d249234b9886244d379f15e6b650b28e3
+  |
+  o  E 7fb047a69f220c21711122dfd94305a9efb60cba
+  |
+  | x  D be0ef73c17ade3fc89dc41701eb9fc3a91b58282
+  | |
+  | | x  C 26805aba1e600a82e93661149f2313866a221a7b
+  | |/
+  | x  B 112478962961147124edd43549aedd1a335e44bf
+  |/
+  | x  I 58e6b987bf7045fcd9c54f496396ca1d1fc81047
+  | |
+  | o  H 575c4b5ec114d64b681d33f8792853568bfb2b2c
+  |/
+  o  A 426bada5c67598ca65036d57d9e4b64b0c1ce7a0
+  
+  $ hg debugobsolete
+  112478962961147124edd43549aedd1a335e44bf 7fb047a69f220c21711122dfd94305a9efb60cba 64a8289d249234b9886244d379f15e6b650b28e3 711f53bbef0bebd12eb6f0511d5e2e998b984846 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  26805aba1e600a82e93661149f2313866a221a7b be0ef73c17ade3fc89dc41701eb9fc3a91b58282 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  be0ef73c17ade3fc89dc41701eb9fc3a91b58282 575c4b5ec114d64b681d33f8792853568bfb2b2c 0 (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  64a8289d249234b9886244d379f15e6b650b28e3 0 {7fb047a69f220c21711122dfd94305a9efb60cba} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}
+  58e6b987bf7045fcd9c54f496396ca1d1fc81047 0 {575c4b5ec114d64b681d33f8792853568bfb2b2c} (Thu Jan 01 00:00:00 1970 +0000) {'user': 'test'}